In order to improve the scintigraphy and radiotherapy of neuroendocrine tumors we synthesized two radioiodinated benzylamines [N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine and N,N-diethyl-2-[125I]iodobenzylamine], analogs of xylamine [N-(2-chloroethyl)-N-ethyl-2-methylbenzylamine]. Xylamine is an irreversible inhibitor of uptake and accumulation of noradrenaline. The two unlabelled iodinated derivatives [N-(2-chloroethyl)-N-ethyl-2-iodobenzylamine and N,N-diethyl-2-iodobenzylamine] were synthesized, purified and checked by HPLC, NMR and mass spectrography. Their affinity for the noradrenaline transporter was determined in vitro on rat brain membrane homogenates with [3H]nisoxetine. Radioiodination was performed by iodide for bromide nucleophilic exchange from brominated precursors. The N,N-diethyl-2-[125I]iodobenzylamine was obtained directly from N,N-diethyl-2-bromobenzylamine. Radiosynthesis of N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine required three steps. A new brominated precursor [N-ethyl-N-(2-bromobenzyl)glycine ethyl ester] which was stable for radiolabelling and suitable for reduction to N-(2-hydroxyethyl)-N-cthyl-2-[125I]iodobenzylamine was synthesized. N-(2-Hydroxyethyl)-N-ethyl-2-[125I]iodobenzylamine was converted to N-(2-chloroethyl)-N-ethyl-2-[125I]iodobenzylamine in the presence of an excess of thionyl chloride. Radioiodinated derivatives were purified and checked by HPLC.
为了改进神经内分泌肿瘤的闪烁成像和放射治疗,我们合成了两种放射性
碘化
苄胺[N-(2-
氯乙基)-N-乙基-2-[125I]
碘苄胺和 N,N-二乙基-2-[125I]
碘苄胺],它们是
二甲胺[N-(2-
氯乙基)-N-乙基-2-甲基
苄胺]的类似物。
二甲胺是
去甲肾上腺素摄取和蓄积的不可逆
抑制剂。我们合成并纯化了两种未标记的
碘化衍
生物[N-(2-
氯乙基)-N-乙基-
2-碘苄胺和 N,N-二乙基-
2-碘苄胺],并通过高效
液相色谱法、核磁共振法和质谱法对其进行了检测。体外用[3H]
尼索西汀测定了它们对大鼠脑膜匀浆中
去甲肾上腺素转运体的亲和力。放射性
碘化是通过
碘化物与
溴化前体的亲核交换进行的。N,N-二乙基-2-[125I]
碘苄胺是直接从 N,N-二乙基-2-
溴苄胺中获得的。N-(2-
氯乙基)-N-乙基-2-[125I]
碘苄胺的放射合成需要三个步骤。我们合成了一种新的
溴化前体[N-乙基-N-(2-
溴苄基)甘
氨酸
乙酯],它对放射性标记稳定,适合还原成 N-(2-羟乙基)-N-辛基-2-[125I]
碘苄胺。在过量亚
硫酰氯的存在下,N-(2-羟乙基)-N-乙基-2-[125I]
碘苄胺转化为 N-(2-
氯乙基)-N-乙基-2-[125I]
碘苄胺。放射性
碘化衍
生物经高效
液相色谱法纯化和检测。